1. Field of the Invention
This invention relates to recording devices, and more particularly to optical disk players.
2. Description of Related Art
Optical disks are recording media which typically contain long strings of microscopic pits representing digitally encoded data. Each string of pits is called a "track". The tracks are formed end to end in a spiral pattern around the center of one or both major surfaces of the disk. Reflected laser light is used to "read" the data encoded in the pits. Common types of optical disks available today include compact disks (CDs), laser video disks, and digital versatile disks (DVDs). Various devices are available for recording data upon and reading data from (i.e., "playing") optical disks.
A compact disk includes several data "channels". A main data channel includes audio or other data (e.g., computer programs or data). There may also be 8 "subcode" channels labeled P-W interleaved with the main data channel. The subcode channels were originally included as a means of placing control data on the disk. For example, the P data channel (P-channel) typically includes information indicating the start and end of each track of an audio CD. The Q-channel conveys a table of contents of the CD including timing information associated with each track, as well as the track type (audio or data).
Channels R-W are reserved for subcode graphics (called CD Graphics) and textual information (known as CD Text). Channels R-W allow graphics and text to be displayed while the data stored on the CD is being accessed. CD Graphics is commonly used to provide song lyrics on a display device during playback of an audio CD. The display of the lyrics is synchronized with the song being played. CD Text is used to provide information about the contents of an audio CD on a display device during playback. Such information may include, for example, the artist's name, the album title, and the title of the song being played.
Audio systems typically include CD players for playing audio CDs. Many CD players have cassettes which have multiple "slots" for storing CDs. Over time, it is difficult for a user to remember what CD is in which slot of the cassette, much less the song titles and corresponding track numbers for each CD in the cassette. Thus in order to play a particular song, it is often necessary for the user to first remove the cassette from the CD player to determine if the desired CD is in the cassette. If the desired CD is in the cassette, the user must determine which slot of the cassette the CD occupies. Then the user must determine which track the desired song is recorded on (e.g., by reading the label on the CD). Finally, the user must program the CD player to access the slot which corresponds to the desired CD, and to play the track number which corresponds to the desired song.
It would thus be desirable to have a system which gathers information about optical disks (e.g., CDs) stored in an optical disk player and provides this information to a user. Such a system would greatly simplify selection of a desired track (e.g., song) for playback. Such a system may also allow the user to select a desired track for playback based upon the optical disk information provided.